Delegatecall in solidity

This is used to call other contract method but any change in states happened in the caller contract not in the targeted contract.

//SPDX-License-Identifier: No-Idea!

pragma solidity >=0.4.16 <0.9.0;

contract A{
    uint public num;
    address public sender;
    uint public value;
    
    function setVars(address _contract, uint _num)public payable{
        (bool success, bytes memory data)= _contract.delegatecall(
                abi.encodeWithSignature("setVars(uint256)", num)
            );
    }
}

contract B{
    uint public num;
    address public sender;
    uint public value;
    
    function setVars(uint _num)public payable{
        num = _num;
        sender = msg.sender;
        value = msg.value;
        
    }
}

By Shabair

Frontend | Blockchain | Smart Contract Developer